Form update empty date in database when i try to update date field using datepicker in laravel

When I try to update my form with date field having jquery datapicker it store empty value on my database so the date field not updated in my form ..I am using date datatype in database for date field..

I added this in html field

<input type="text" id="datepicker" value="" name="datatime">

This is inside my controller

$site->update([
            'name'=>$request['name'],
            'copyright'=> $request['copyright'],
            'is_active'=>$request['status'] == 'true' ? 1 : 0,
            'message'=>$request['message'],
            'datatime'=>$request['datetime'],
            'url'=>$request['url'],
            'metadata'=>$request['metadata']

        ]);

via Karthiga